Characterizing Winter Flounder Nursery Areas Using Otolith Microstructure and Microchemical Techniques

A preliminary study, using young-of-the-year winter flounder from 12 nursery areas from New Jersey to New Hampshire, is being conducted to establish the effectiveness of using otolith microstructure and microchemical techniques for productive nursery area identification.  Using microstructure analysis, spatial variation in growth rates and early life history parameters between nursery grounds is examined. Identifying differences in the growth rates provides a way to rank the quality of each nursery area at a specific point in time. Understanding the timing of life history events in specific nursery areas also can be used to promote successful recruitment by indicating when and where habitat protection is most critical. Geographic variation in otolith microchemistry is being examined using solution-based inductively coupled plasma mass spectrometry (SB-ICP-MS). Establishing natural tags through microchemical analysis may be an effective method to assess stock structure, migration patterns, and connectivity between adult populations and nursery sources. This study helps determine the scale at which elemental signatures are site-specific. Information gained from this preliminary study has the potential to assist in developing models for critical winter flounder nursery characteristics for use in conservation policy.